In electronic systems such as those in an automobile, electronic control units (ECUs) distributed around a vehicle are typically connected to a communication bus, such as the Controller Area Network (CAN) bus which is well-known in industrial and automotive applications. In use, voltage differences between different (ECUs) on the bus, due for instance to differences in ground potential at the different ECUs, can cause communication errors.
It has been proposed to overcome this problem by use of opto-isolators to isolate the signals produced by different ECUs. However, such a proposal has a number of drawbacks: firstly, opto-isolators are expensive; secondly, the reliability of opto-isolators may not be sufficiently robust to withstand the exacting mechanical and temperature conditions produced in an automotive environment.
It is an object of the present invention to provide an interface circuit and method for digital signals, wherein the above-mentioned disadvantages may be overcome or at least alleviated.